<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        
    </style>
</head>
<body>
    
</body>
<script>

    
    // 条件 ? 值1 : 值2
    

    // var year = 2024;
    // var res = year%4===0 && year%100 !==0 || year%400 === 0 ? "是闰年" : "不是闰年";
    // console.log(res);


    // var n = 5;
    // n = n < 10 ? "0" + n : n;
    // console.log(n);


    // var a = true ? console.log("hello") : console.log('world')
    // console.log( a )


</script>
</html>